Huge Asteroid Size Comparison | 251km to 600km Diameter
(55637) 2002 UX25 is a possible dwarf planet that orbits the Sun in the Kuiper belt beyond Neptune. Its orbit takes roughly 280 years, and it has one known moon. This moon makes it much easier to calculate mass, and when the size is known, also is density. The low density of about 0.82 g/cm3 surprised astronomers.